1. Field of the Invention
The invention relates to a system for recording and/or reproducing information, comprising a magnetizable medium provided with a track pattern comprising
buried servotracks of a first type containing a first signal, and PA1 buried servotracks of a second type containing a second signal, which servotracks extend substantially in a longitudinal direction and which track pattern, in a transverse direction perpendicular to the longitudinal direction, alternately comprises a servotrack of the first type followed by a servotrack of the second type, and an apparatus comprising PA1 a magnetic head unit comprising a plurality of heads at different positions in the transverse direction, PA1 means for moving the medium relative to the magnetic head unit in the longitudinal direction, PA1 an actuator for moving the magnetic head unit relative to the medium in the transverse direction, and PA1 a control unit for controlling the actuator, which control unit is adapted to generate a position signal based on the difference between the signals of two heads. PA1 the bands of the first type comprising N1 servotracks having a first typical width W1, PA1 the bands of the second type comprising N2 servotracks having a second typical width W2, which complies with EQU N2=2, 4, 6 etc. and W2=(k+1/2)W1 PA1 which bands of the first type comprising N1 servotracks having a first typical width W1, PA1 the bands of the second type comprising N2 servotracks having a second typical width W2, which complies with EQU N2=2, 4, 6 etc. and W2=(k+1/2)W1 PA1 the structure comprises a group of at least two bands of a first type, which are separated by a band of a second type, PA1 the bands of the first type adjoin a write gap at their sides remote from the band of the second type, PA1 the bands of the first type have N1 write gaps having a first typical width W1 and PA1 the band of the second type has N2 write gaps having a second typical width W2, which complies with EQU N2=2, 4, 6 etc. and W2=(k+1/2)W1
The invention also relates to a medium for such a system.
The invention further relates to a magnetic head comprising a head face with a longitudinal direction in which a magnetizable medium is movable relative to the magnetic head, and a transverse direction oriented transversely to the longitudinal direction, and further comprising a structure of integrated write units, which structure terminates in the head face, which write units are disposed adjacent one another in the transverse direction, extend substantially in the transverse direction and each have a write gap.
2. Description of Related Art
Such a medium, such a system and such a magnetic head are known from WO 96/30897-A2. The known medium is a magnetic tape on which seven servotracks have been written by means of the known magnetic head, the signal in the first servotrack being in phase with the signal in the third, the fifth and the seventh servotrack and the signals in the second, the fourth and the sixth servotrack being in phase opposition to the signals in the first, the third and the fifth servotrack. By means of an apparatus forming part of the known system it is possible to write information signals over the servotracks on the magnetic tape thus formatted. For this purpose, the apparatus comprises a magnetic head unit having four heads and means for moving the magnetic tape past the magnetic head unit in a longitudinal direction. The known apparatus further comprises an actuator for positioning the magnetic head unit in a transverse direction and a control unit for controlling the actuator. The control circuit comprises a comparator for generating a position signal based on the difference between the signal supplied by a first head and the signal supplied by a second head. The magnetic head unit follows the servotracks on the magnetic tape on the basis of the position signal. A disadvantage of the known system, the known medium and the known magnetic head is that after the whole magnetic tape has been written or read the magnetic tape is to be rewound in order to return it into its initial position. Another disadvantage of the known system is that only one half of the number of heads supplies information about the position of the servotracks relative to the magnetic head unit.